Piezoelectric ultrasonic driving metal plate deep drawing forming device and method

Abstract

The application belongs to the technical field of material processing forming, and particularly relates to a piezoelectric ultrasonic driving metal plate deep drawing forming device and method. The deep drawing forming device comprises a female die body and a punch. An ultrasonic driving module is arranged on a placement end face of the female die body. The ultrasonic driving module comprises a die insert block and a piezoelectric ceramic sheet. The piezoelectric ceramic sheet is located between the die insert block and the placement end face. A metal plate is placed on the die insert block and is pressed on the placement end face by a blank holder. The piezoelectric ceramic sheet is connected with an ultrasonic generating device. The ultrasonic driving module can implement directional and quantitative driving force loading on the surface of a dangerous deformation area of the metal plate, especially a complex thin-walled component. The harmful friction resistance in the traditional deformation is converted into beneficial friction power, so that the effect of actively pushing the plate blank into the die cavity is achieved.

Description

Technical Field

[0001] This invention belongs to the field of material processing and forming technology, specifically relating to a piezoelectric ultrasonic-driven metal sheet deep drawing forming device and method. Background Technology

[0002] Deep drawing, which involves applying complex external forces to sheet metal using a die, induces complex stress states within the sheet and promotes flow in an ideal direction, plays a crucial role in equipment manufacturing. This has led to a demand for high-performance, high-reliability, lightweight, and highly efficient structural parts. These parts are typically used in extremely harsh environments, generally employing lightweight, high-strength materials that are difficult to deform. They exhibit poor plasticity at room temperature, are prone to wrinkling and cracking, and possess characteristics such as complex shapes, high precision, thin walls, and extreme combinations of large and small geometric dimensions, making precise deep drawing a significant challenge.

[0003] To address the aforementioned issues, scholars have developed numerous novel and unique deep-drawing processes. Among them, ultrasonic vibration-assisted forming is an advanced high-energy rapid forming technology. By applying an ultrasonic energy field during sheet metal deformation, the surface and volume effects generated by the ultrasonic energy field excitation can effectively improve the forming limit of difficult-to-form materials and the surface quality of the product, while simultaneously reducing the material's deformation resistance. This demonstrates significant advantages in reducing the tonnage of forming equipment and production costs. Although the ultrasonic surface effect reduces the frictional resistance between the blank and the die, the accompanying dynamic plastic deformation of the metal and the continuous change of new friction surfaces in the high-pressure contact area limit the lubrication effect. Furthermore, current ultrasonic-assisted deep-drawing processes for thin-walled components mostly employ integral one-dimensional reciprocating longitudinal or radial vibration. While this mode can reduce metal forming forces and improve workpiece surface quality, for some complex thin-walled components, due to the varying deformation patterns and stress states in different regions, integral one-dimensional reciprocating vibration cannot achieve the ideal forming effect.

[0004] Therefore, there is an urgent need to develop new principles and technologies for high-performance precision forming and manufacturing of complex thin-walled components made of lightweight materials to meet the needs of equipment and industrial development. Summary of the Invention

[0005] The purpose of this invention is to improve the surface quality of workpieces drawn from metal sheets and to increase the forming limit of difficult-to-form materials, by providing a piezoelectric ultrasonic-driven metal sheet deep drawing device and method.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] A piezoelectric ultrasonic-driven metal sheet deep drawing device includes a die body and a punch, characterized in that: an ultrasonic driving module is provided on the placement end face of the die body, the ultrasonic driving module includes: a die insert and a piezoelectric ceramic sheet, the piezoelectric ceramic sheet is located between the die insert and the placement end face, the metal sheet is placed on the die insert, and the metal sheet is pressed onto the placement end face by a pressing ring; the piezoelectric ceramic sheet is connected to an ultrasonic generator.

[0008] Furthermore, the ultrasonic drive module is installed at a location where the metal sheet undergoes severe uneven deformation during deep drawing; the ultrasonic drive module is embedded in a portion of the placement end face, and the upper surface of the mold insert is flush with other areas of the placement end face.

[0009] Furthermore, the mold insert includes an insert body and a plurality of protrusions disposed on the insert body.

[0010] Furthermore, the protrusion is a cuboid or a hemisphere.

[0011] This invention also discloses a piezoelectric ultrasonic-driven deep drawing method for metal sheets, comprising the following steps:

[0012] S1. Place the metal sheet between the die body and the pressure ring, and apply pressure to the pressure ring to press the metal sheet.

[0013] S2. Apply pressure to the punch and simultaneously turn on the ultrasonic generator. Utilize the inverse piezoelectric effect of the piezoelectric ceramic sheet to excite a modal response at the modal frequency of the mold insert. The protrusion of the mold insert achieves a cyclical transformation of initial position - peak - middle position - trough - initial position through up-down fluctuations. Under the pressure of the pressure ring, the mold insert drives the metal sheet in a unidirectional continuous friction along an elliptical trajectory.

[0014] Furthermore, under the combined action of the punch pressure and the driving force of the ultrasonic drive module, the metal sheet gradually adheres to the mold cavity of the die body.

[0015] Furthermore, two modal responses with equal amplitude and a temporal and spatial difference of π / 2 are excited at the modal frequency of the mold insert. These two responses are superimposed to form a continuously unidirectional traveling wave.

[0016] The beneficial effects of the piezoelectric ultrasonic-driven metal sheet deep drawing device and method of the present invention are:

[0017] 1. The present invention uses an ultrasonic drive module to apply directional and quantitative driving force to the surface of metal plates, especially complex thin-walled components in dangerous deformation areas, thereby converting the harmful frictional resistance in traditional deformation into beneficial frictional power, and achieving the effect of actively pushing the slab into the mold cavity.

[0018] 2. The present invention uses ultrasonic drive to improve the deep drawing limit of metal sheets and the surface quality of products, while reducing the material deformation resistance, reducing the tonnage of forming equipment and production costs. By actively coordinating and intelligently controlling the magnitude, regional distribution and punch pressure of ultrasonic driving force, it can meet the requirements of high-performance precision forming. Attached Figure Description

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0020] Figure 1 This is a schematic diagram of sheet metal deep drawing.

[0021] Figure 2 This is a cross-sectional view of the piezoelectric ultrasonic-driven metal sheet deep drawing device of Embodiment 1 of the present invention;

[0022] Figure 3 yes Figure 2 Enlarged view of section A in the middle;

[0023] Figure 4 This is a cross-sectional view of the die body of Embodiment 1 of the present invention;

[0024] Figure 5 This is a schematic diagram illustrating the principle of piezoelectric ultrasonic-driven deep drawing of metal sheets according to Embodiment 1 of the present invention;

[0025] Figure 6 This is a cross-sectional view of the mold insert in Embodiment 2 of the present invention.

[0026] In the figure: 1. Punch, 2. Die body, 21. Placement end face, 22. Mold cavity, 3. Mold insert, 31. Insert body, 32. Protrusion, 4. Piezoelectric ceramic sheet, 5. Metal sheet, 51. Part, 6. Pressure ring. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0028] Example 1

[0029] like Figures 1-4 The present invention provides a specific embodiment of a piezoelectric ultrasonic-driven metal sheet deep drawing forming device. The die body 2 is used to place the metal sheet 5, including a die cavity 22 and a placement end face 21; the punch 1 faces the die cavity 22 and performs deep drawing deformation on the metal sheet 5.

[0030] See Figure 1 This embodiment describes the entire process of deforming the metal sheet 5, taking the deep drawing of the metal sheet 5 as an example. The metal sheet 5 is deep drawn into the shape of part 51 by the punch 1.

[0031] See Figures 2-5 A piezoelectric ultrasonic-driven metal sheet deep drawing forming device includes a die body 2 and a punch 1. An ultrasonic driving module is provided on the placement end face 21 of the die body 2. The ultrasonic driving module is located at the position where the deep drawing deformation of the metal sheet 5 is more uneven and severe. The ultrasonic driving module includes a die insert 3 and a piezoelectric ceramic sheet 4. The piezoelectric ceramic sheet 4 is located between the die insert 3 and the placement end face 21. The metal sheet 5 is placed on the die insert 3 and pressed onto the placement end face 21 by a pressure ring 6. The piezoelectric ceramic sheet 4 is connected to an ultrasonic generator. The ultrasonic driving module is embedded in a part of the placement end face 21, and the upper surface of the die insert 3 is flush with the other parts of the placement end face 21.

[0032] Based on the shape and material of the metal sheet 5 to be drawn, through stress analysis and / or through multiple tests and verifications, the area on the die body 2 where the metal sheet 5 is prone to uneven deformation and severe deformation during the deep drawing process is identified. A groove is machined in this area of ​​the die body 2, the ultrasonic drive module is installed in the groove, and the upper surface of the mold insert 3 is flush with the other parts of the placement end face 21 of the die body 2.

[0033] To enhance the frictional driving effect of the mold insert 3, the mold insert 3 includes an insert body 31 and a plurality of protrusions 32 disposed on the insert body 31. In this embodiment, the protrusions 32 are cuboids.

[0034] The piezoelectric ultrasonic-driven deep drawing method for metal sheets according to an embodiment of the present invention includes the following steps:

[0035] S1. Select the appropriate die body 2, pressure ring 6 and punch 1 according to the shape and size of the metal sheet 5;

[0036] S2. Place the metal sheet 5 between the die body 2 and the pressure ring 6, and apply pressure to the pressure ring 6 to press the metal sheet 5. Perform a deep drawing test and repeat the test multiple times to find the area on the placement end face 21 of the die body 2 where the metal sheet 5 is deformed unevenly and severely. Install the piezoelectric ceramic sheet 4 and the mold insert 3 in this area. The upper surface of the mold insert 3 is flush with the other areas of the placement end face 21.

[0037] S3. Deep drawing of metal sheet 5: Place the metal sheet 5 to be deep drawn between the die body 2 and the pressure ring 6, and apply pressure to the pressure ring 6 to press the metal sheet 5.

[0038] S4. Apply pressure to punch 1 and simultaneously turn on the ultrasonic generator. Utilize the inverse piezoelectric effect of piezoelectric ceramic sheet 4 to excite a modal response at the modal frequency of mold insert 3. The protrusion 32 of mold insert 3 achieves a cyclical transformation of initial position-peak-middle position-trough-initial position through up-down fluctuations. Under the pressure of the pressure ring 6, the mold insert 3 achieves unidirectional continuous friction driving of metal sheet 5 in an elliptical trajectory. Under the pressure of punch 1 and ultrasonic driving, metal sheet 5 gradually adheres to the mold cavity 22 of the die body 2.

[0039] In a preferred embodiment, two modal responses of equal amplitude with a temporal and spatial difference of π / 2 can be excited at the modal frequency of the mold insert 3. These two responses are superimposed to form a continuously unidirectional traveling wave. See also Figure 5 As shown, within a period from 0 to T, the surface particles P of the mold insert 3 are at the same horizontal position. Through up-down fluctuations, the initial position-peak-middle position-trough-initial position cycle is achieved. Under the pressure of the pressure ring 6, the mold insert 3 drives the metal plate 5 in a unidirectional continuous friction along an elliptical trajectory, and finally sends the plate into the mold cavity 22.

[0040] As another preferred implementation, two modal responses with equal amplitude and a temporal and spatial difference of π / 4 are excited at the modal frequency of the mold insert 3. These two responses are superimposed to form a continuously unidirectional traveling wave.

[0041] Of course, a single modal response can also achieve frictional drive, and multiple modal responses can have different amplitudes.

[0042] Example 2

[0043] See Figure 6 As another preferred method for mold insert 3, protrusion 32 is hemispherical.

[0044] It should be understood that the specific embodiments described above are for illustrative purposes only and are not intended to limit the scope of the invention. Obvious variations or modifications derived from the spirit of the invention are still within the protection scope of the invention.

Claims

1. A piezoelectric ultrasonic-driven metal sheet deep drawing device, comprising a die body (2) and a punch (1), characterized in that: An ultrasonic driving module is provided on the placement end face (21) of the die body (2). The ultrasonic driving module includes a die insert (3) and a piezoelectric ceramic sheet (4). The piezoelectric ceramic sheet (4) is located between the die insert (3) and the placement end face (21). The metal plate (5) is placed on the die insert (3) and pressed onto the placement end face (21) by the pressure ring (6). The piezoelectric ceramic sheet (4) is connected to an ultrasonic generator. Based on the shape and material of the metal sheet (5) to be drawn, through stress analysis and / or through multiple tests and verifications, the area on the die body (2) where the metal sheet (5) is prone to uneven deformation and severe deformation during the deep drawing process is found. A groove is machined in this area of ​​the die body (2), and the ultrasonic drive module is installed in the groove. The ultrasonic drive module is embedded in a part of the placement end face (21), and the upper surface of the mold insert (3) is flush with other areas of the placement end face (21). The mold insert (3) includes an insert body (31) and multiple protrusions (32) provided on the insert body (31). Modal response is excited at the modal frequency of the mold insert (3) by utilizing the inverse piezoelectric effect of the piezoelectric ceramic sheet (4); the protrusion (32) of the mold insert (3) achieves the cyclic transformation of initial position-peak-middle position-trough-initial position through up and down fluctuations, and under the pressure of the pressure ring (6), the mold insert (3) drives the metal plate (5) in a unidirectional continuous friction with an elliptical trajectory.

2. The piezoelectric ultrasonic-driven metal sheet deep drawing device according to claim 1, characterized in that: The protrusion (32) is a cuboid or a hemisphere.

3. A piezoelectric ultrasonic-driven deep drawing method for metal sheets, utilizing the deep drawing apparatus described in claim 1, characterized in that, Includes the following steps: S1. Place the metal sheet (5) between the die body (2) and the pressure ring (6), and apply pressure to the pressure ring (6) to press the metal sheet (5). S2. Apply pressure to the punch (1) and turn on the ultrasonic generator at the same time. Use the inverse piezoelectric effect of the piezoelectric ceramic sheet (4) to excite the modal response at the modal frequency of the mold insert (3). The protrusion (32) of the mold insert (3) realizes the cyclic transformation of initial position - peak - middle position - valley - initial position through up and down fluctuation. Under the pressure of the pressure ring (6), the mold insert (3) drives the metal plate (5) in a unidirectional continuous friction with an elliptical trajectory.

4. The piezoelectric ultrasonic-driven deep drawing method for metal sheets according to claim 3, characterized in that: Under the combined action of the pressure of the punch (1) and the drive of the ultrasonic drive module, the metal sheet (5) gradually adheres to the mold cavity (22) of the die body (2).

5. A piezoelectric ultrasonic-driven deep drawing method for metal sheets according to claim 3 or 4, characterized in that: Two modal responses with equal amplitude and a time and space difference of π / 2 are excited at the modal frequency of the mold insert (3). These two responses are superimposed to form a traveling wave that travels continuously in one direction.

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